import java.util.ArrayList;
import java.util.Iterator;

/**
 * Creat with IntelliJ IDEA
 * Description:
 * User:WZW
 * Date:2021-12-04
 * Time:9:34
 */
public class TestDemo {
    public static void main(String[] args) {
        String str1 = "welcome to bit";
        String str2 = "come";
        ArrayList<Character> string = new ArrayList<>();
        for (int i = 0; i < str1.length(); i++) {
            if (str2.contains(str1.charAt(i)+"")==false){
                string.add(str1.charAt(i));
            }
        }
        System.out.println(string);
    }

}
